2 Information regarding the Enhanced IDE drive in Linux 2.6
4 ==============================================================================
7 The hdparm utility can be used to control various IDE features on a
8 running system. It is packaged separately. Please Look for it on popular
13 *** IMPORTANT NOTICES: BUGGY IDE CHIPSETS CAN CORRUPT DATA!!
15 *** PCI versions of the CMD640 and RZ1000 interfaces are now detected
16 *** automatically at startup when PCI BIOS support is configured.
18 *** Linux disables the "prefetch" ("readahead") mode of the RZ1000
19 *** to prevent data corruption possible due to hardware design flaws.
21 *** For the CMD640, linux disables "IRQ unmasking" (hdparm -u1) on any
22 *** drive for which the "prefetch" mode of the CMD640 is turned on.
23 *** If "prefetch" is disabled (hdparm -p8), then "IRQ unmasking" can be
26 *** For the CMD640, linux disables "32bit I/O" (hdparm -c1) on any drive
27 *** for which the "prefetch" mode of the CMD640 is turned off.
28 *** If "prefetch" is enabled (hdparm -p9), then "32bit I/O" can be
31 *** The CMD640 is also used on some Vesa Local Bus (VLB) cards, and is *NOT*
32 *** automatically detected by Linux. For safe, reliable operation with such
33 *** interfaces, one *MUST* use the "ide0=cmd640_vlb" kernel option.
35 *** Use of the "serialize" option is no longer necessary.
37 ================================================================================
40 - 40-conductor IDE cables are capable of transferring data in DMA modes up to
43 - If possible devices should be attached to separate channels if they are
44 available. Typically the disk on the first and CD-ROM on the second.
46 - If you mix devices on the same cable, please consider using similar devices
47 in respect of the data transfer mode they support.
49 - Even better try to stick to the same vendor and device type on the same
52 ================================================================================
54 This is the multiple IDE interface driver, as evolved from hd.c.
56 It supports up to 9 IDE interfaces per default, on one or more IRQs (usually
57 14 & 15). There can be up to two drives per interface, as per the ATA-6 spec.
59 Primary: ide0, port 0x1f0; major=3; hda is minor=0; hdb is minor=64
60 Secondary: ide1, port 0x170; major=22; hdc is minor=0; hdd is minor=64
61 Tertiary: ide2, port 0x1e8; major=33; hde is minor=0; hdf is minor=64
62 Quaternary: ide3, port 0x168; major=34; hdg is minor=0; hdh is minor=64
63 fifth.. ide4, usually PCI, probed
64 sixth.. ide5, usually PCI, probed
66 To access devices on interfaces > ide0, device entries please make sure that
67 device files for them are present in /dev. If not, please create such
68 entries, by simply running the included shell script:
70 /usr/src/linux/scripts/MAKEDEV.ide
72 This driver automatically probes for most IDE interfaces (including all PCI
73 ones), for the drives/geometries attached to those interfaces, and for the IRQ
74 lines being used by the interfaces (normally 14, 15 for ide0/ide1).
76 For special cases, interfaces may be specified using kernel "command line"
79 ide3=0x168,0x36e,10 /* ioports 0x168-0x16f,0x36e, irq 10 */
81 Normally the irq number need not be specified, as ide.c will probe for it:
83 ide3=0x168,0x36e /* ioports 0x168-0x16f,0x36e */
85 The standard port, and irq values are these:
92 Note that the first parameter reserves 8 contiguous ioports, whereas the
93 second value denotes a single ioport. If in doubt, do a 'cat /proc/ioports'.
95 In all probability the device uses these ports and IRQs if it is attached
96 to the appropriate ide channel. Pass the parameter for the correct ide
97 channel to the kernel, as explained above.
99 Any number of interfaces may share a single IRQ if necessary, at a slight
100 performance penalty, whether on separate cards or a single VLB card.
101 The IDE driver automatically detects and handles this. However, this may
102 or may not be harmful to your hardware.. two or more cards driving the same IRQ
103 can potentially burn each other's bus driver, though in practice this
104 seldom occurs. Be careful, and if in doubt, don't do it!
106 Drives are normally found by auto-probing and/or examining the CMOS/BIOS data.
107 For really weird situations, the apparent (fdisk) geometry can also be specified
108 on the kernel "command line" using LILO. The format of such lines is:
110 hdx=cyls,heads,sects,wpcom,irq
113 where hdx can be any of hda through hdh, Three values are required
114 (cyls,heads,sects). For example:
116 hdc=1050,32,64 hdd=cdrom
118 either {hda,hdb} or {hdc,hdd}. The results of successful auto-probing may
119 override the physical geometry/irq specified, though the "original" geometry
120 may be retained as the "logical" geometry for partitioning purposes (fdisk).
122 If the auto-probing during boot time confuses a drive (ie. the drive works
123 with hd.c but not with ide.c), then an command line option may be specified
124 for each drive for which you'd like the drive to skip the hardware
125 probe/identification sequence. For example:
132 Note that when only one IDE device is attached to an interface, it should be
133 jumpered as "single" or "master", *not* "slave". Many folks have had
134 "trouble" with cdroms because of this requirement, so the driver now probes
135 for both units, though success is more likely when the drive is jumpered
138 Courtesy of Scott Snyder and others, the driver supports ATAPI cdrom drives
139 such as the NEC-260 and the new MITSUMI triple/quad speed drives.
140 Such drives will be identified at boot time, just like a hard disk.
142 If for some reason your cdrom drive is *not* found at boot time, you can force
143 the probe to look harder by supplying a kernel command line parameter
146 hdc=cdrom /* hdc = "master" on second interface */
148 hdd=cdrom /* hdd = "slave" on second interface */
150 For example, a GW2000 system might have a hard drive on the primary
151 interface (/dev/hda) and an IDE cdrom drive on the secondary interface
152 (/dev/hdc). To mount a CD in the cdrom drive, one would use something like:
154 ln -sf /dev/hdc /dev/cdrom
156 mount /dev/cdrom /mnt/cdrom -t iso9660 -o ro
158 If, after doing all of the above, mount doesn't work and you see
159 errors from the driver (with dmesg) complaining about `status=0xff',
160 this means that the hardware is not responding to the driver's attempts
161 to read it. One of the following is probably the problem:
163 - Your hardware is broken.
165 - You are using the wrong address for the device, or you have the
166 drive jumpered wrong. Review the configuration instructions above.
168 - Your IDE controller requires some nonstandard initialization sequence
169 before it will work properly. If this is the case, there will often
170 be a separate MS-DOS driver just for the controller. IDE interfaces
171 on sound cards usually fall into this category. Such configurations
172 can often be made to work by first booting MS-DOS, loading the
173 appropriate drivers, and then warm-booting linux (without powering
174 off). This can be automated using loadlin in the MS-DOS autoexec.
176 If you always get timeout errors, interrupts from the drive are probably
177 not making it to the host. Check how you have the hardware jumpered
178 and make sure it matches what the driver expects (see the configuration
179 instructions above). If you have a PCI system, also check the BIOS
180 setup; I've had one report of a system which was shipped with IRQ 15
181 disabled by the BIOS.
183 The kernel is able to execute binaries directly off of the cdrom,
184 provided it is mounted with the default block size of 1024 (as above).
186 Please pass on any feedback on any of this stuff to the maintainer,
187 whose address can be found in linux/MAINTAINERS.
189 Note that if BOTH hd.c and ide.c are configured into the kernel,
190 hd.c will normally be allowed to control the primary IDE interface.
191 This is useful for older hardware that may be incompatible with ide.c,
192 and still allows newer hardware to run on the 2nd/3rd/4th IDE ports
193 under control of ide.c. To have ide.c also "take over" the primary
194 IDE port in this situation, use the "command line" parameter: ide0=0x1f0
196 The IDE driver is modularized. The high level disk/CD-ROM/tape/floppy
197 drivers can always be compiled as loadable modules, the chipset drivers
198 can only be compiled into the kernel, and the core code (ide.c) can be
199 compiled as a loadable module provided no chipset support is needed.
201 When using ide.c as a module in combination with kmod, add:
203 alias block-major-3 ide-probe
205 to /etc/modprobe.conf.
207 When ide.c is used as a module, you can pass command line parameters to the
208 driver using the "options=" keyword to insmod, while replacing any ',' with
211 insmod ide.o options="ide0=serialize ide1=serialize ide2=0x1e8;0x3ee;11"
214 ================================================================================
216 Summary of ide driver parameters for kernel command line
217 --------------------------------------------------------
219 "hdx=" is recognized for all "x" from "a" to "h", such as "hdc".
221 "idex=" is recognized for all "x" from "0" to "3", such as "ide1".
223 "hdx=noprobe" : drive may be present, but do not probe for it
225 "hdx=none" : drive is NOT present, ignore cmos and do not probe
227 "hdx=nowerr" : ignore the WRERR_STAT bit on this drive
229 "hdx=cdrom" : drive is present, and is a cdrom drive
231 "hdx=cyl,head,sect" : disk drive is present, with specified geometry
233 "hdx=remap" : remap access of sector 0 to sector 1 (for EZDrive)
235 "hdx=remap63" : remap the drive: add 63 to all sector numbers
238 "hdx=autotune" : driver will attempt to tune interface speed
239 to the fastest PIO mode supported,
240 if possible for this drive only.
241 Not fully supported by all chipset types,
242 and quite likely to cause trouble with
243 older/odd IDE drives.
245 "hdx=swapdata" : when the drive is a disk, byte swap all data
247 "hdx=bswap" : same as above..........
249 "hdx=scsi" : the return of the ide-scsi flag, this is useful for
250 allowing ide-floppy, ide-tape, and ide-cdrom|writers
251 to use ide-scsi emulation on a device specific option.
253 "hdxlun=xx" : set the drive last logical unit
255 "idebus=xx" : inform IDE driver of VESA/PCI bus speed in MHz,
256 where "xx" is between 20 and 66 inclusive,
257 used when tuning chipset PIO modes.
258 For PCI bus, 25 is correct for a P75 system,
259 30 is correct for P90,P120,P180 systems,
260 and 33 is used for P100,P133,P166 systems.
261 If in doubt, use idebus=33 for PCI.
262 As for VLB, it is safest to not specify it.
263 Bigger values are safer than smaller ones.
265 "idex=noprobe" : do not attempt to access/use this interface
267 "idex=base" : probe for an interface at the addr specified,
268 where "base" is usually 0x1f0 or 0x170
269 and "ctl" is assumed to be "base"+0x206
271 "idex=base,ctl" : specify both base and ctl
273 "idex=base,ctl,irq" : specify base, ctl, and irq number
275 "idex=autotune" : driver will attempt to tune interface speed
276 to the fastest PIO mode supported,
277 for all drives on this interface.
278 Not fully supported by all chipset types,
279 and quite likely to cause trouble with
280 older/odd IDE drives.
282 "idex=noautotune" : driver will NOT attempt to tune interface speed
283 This is the default for most chipsets,
286 "idex=serialize" : do not overlap operations on idex. Please note
287 that you will have to specify this option for
288 both the respecitve primary and secondary channel
291 "idex=four" : four drives on idex and ide(x^1) share same ports
293 "idex=reset" : reset interface after probe
295 "idex=dma" : automatically configure/use DMA if possible.
297 "idex=ata66" : informs the interface that it has an 80c cable
298 for chipsets that are ATA-66 capable, but the
299 ability to bit test for detection is currently
302 "ide=reverse" : formerly called to pci sub-system, but now local.
304 The following are valid ONLY on ide0 (except dc4030), which usually corresponds
305 to the first ATA interface found on the particular host, and the defaults for
306 the base,ctl ports must not be altered.
308 "ide0=dtc2278" : probe/support DTC2278 interface
309 "ide0=ht6560b" : probe/support HT6560B interface
310 "ide0=cmd640_vlb" : *REQUIRED* for VLB cards with the CMD640 chip
311 (not for PCI -- automatically detected)
312 "ide0=qd65xx" : probe/support qd65xx interface
313 "ide0=ali14xx" : probe/support ali14xx chipsets (ALI M1439/M1443/M1445)
314 "ide0=umc8672" : probe/support umc8672 chipsets
315 "idex=dc4030" : probe/support Promise DC4030VL interface
316 "ide=doubler" : probe/support IDE doublers on Amiga
318 There may be more options than shown -- use the source, Luke!
320 Everything else is rejected with a "BAD OPTION" message.
322 ================================================================================
324 IDE ATAPI streaming tape driver
325 -------------------------------
327 This driver is a part of the Linux ide driver and works in co-operation
328 with linux/drivers/block/ide.c.
330 The driver, in co-operation with ide.c, basically traverses the
331 request-list for the block device interface. The character device
332 interface, on the other hand, creates new requests, adds them
333 to the request-list of the block device, and waits for their completion.
335 Pipelined operation mode is now supported on both reads and writes.
337 The block device major and minor numbers are determined from the
338 tape's relative position in the ide interfaces, as explained in ide.c.
340 The character device interface consists of the following devices:
342 ht0 major 37, minor 0 first IDE tape, rewind on close.
343 ht1 major 37, minor 1 second IDE tape, rewind on close.
345 nht0 major 37, minor 128 first IDE tape, no rewind on close.
346 nht1 major 37, minor 129 second IDE tape, no rewind on close.
349 Run linux/scripts/MAKEDEV.ide to create the above entries.
351 The general magnetic tape commands compatible interface, as defined by
352 include/linux/mtio.h, is accessible through the character device.
354 General ide driver configuration options, such as the interrupt-unmask
355 flag, can be configured by issuing an ioctl to the block device interface,
356 as any other ide device.
358 Our own ide-tape ioctl's can be issued to either the block device or
359 the character device interface.
361 Maximal throughput with minimal bus load will usually be achieved in the
364 1. ide-tape is operating in the pipelined operation mode.
365 2. No buffering is performed by the user backup program.
369 ================================================================================
373 IDE = Integrated Drive Electronics, meaning that each drive has a built-in
374 controller, which is why an "IDE interface card" is not a "controller card".
376 ATA = AT (the old IBM 286 computer) Attachment Interface, a draft American
377 National Standard for connecting hard drives to PCs. This is the official
380 The latest standards define some enhancements, known as the ATA-6 spec,
381 which grew out of vendor-specific "Enhanced IDE" (EIDE) implementations.
383 ATAPI = ATA Packet Interface, a new protocol for controlling the drives,
384 similar to SCSI protocols, created at the same time as the ATA2 standard.
385 ATAPI is currently used for controlling CDROM, TAPE and FLOPPY (ZIP or
386 LS120/240) devices, removable R/W cartridges, and for high capacity hard disk
392 Wed Apr 17 22:52:44 CEST 2002 edited by Marcin Dalecki, the current
395 Wed Aug 20 22:31:29 CEST 2003 updated ide boot uptions to current ide.c
396 comments at 2.6.0-test4 time. Maciej Soltysiak <solt@dns.toxicfilms.tv>